Some seeders or drills allow the simultaneous distribution of two or more granular products, for example seeds and a granular fertilizer, in a single pass. However, in most cases, the drills either distribute the two products in a mixed state or in separate rows, without being able to perform in the two configurations. Some farmers thus have to purchase two different types of seeders or drills.
Some prior art seeders or drills allow products from different tanks to selectively mix by having one conduit per product, with selectively openable and closable connections between the conduits such that the product from one conduit can be diverted into another conduit to be mixed with the product transported therein. The mixed products are thus generally delivered in a single conduit, while the separate products are delivered in several separate conduits. The use of different delivery systems for delivering separate and mixed products to the seeding units can render the seeder or drill relatively complex.
Other prior art seeders allow products from separate tanks, which can be distributed separately, to selectively mix in one of the tanks by opening a trap therebetween, such as to be distributed together. However, since the two products are mixed in the tank to be distributed together, the excess product which is not distributed cannot be individually recuperated and removed from the seeder. Moreover, here again different delivery systems are generally required for the separate and mixed product configurations.
Accordingly, improvements are desirable.